Analysis of Dam Overtopping by Considering Hydraulic and Hydrological Uncertainties

Document Type : Research Article

Authors

1 PhD Candidate, School of Civil Engineering, Iran University of Science and Technology

2 Assistant Professor, School of Civil Engineering, Iran University of Science and Technology

Abstract

Adequate determination of dam overtopping risk by considering random variables uncertainty is an important issue in the design of earthfill dam. Therefore, ignoring these uncertainties cause overestimation or underestimation of dam height. Uncertainties of rainfall and flood have more effect on overtopping risk. In this study, flood hydrograph was generated by considering uncertainness of rainfall and rainfall-runoff parameters with using developed model named RPG (Rain Pattern Generator) and HEC1 models. In addition, overtopping risk of Jamishan dam was estimated by using the Monte Carlo simulation (MCs). The effect of main variables such as spillway width, dam height and normal water level on risk of dam overtopping was evaluated by considering related variants. Results show that average variation rate of dam overtopping risk was 0.03 based on unit variation of spillway width. Also average variation rate of overtopping risk was respectively 3.1 and 1.56 based on unit variation of normal water level and dam height. Therefore, variation of flood control volume is more effective on risk of dam overtopping than spillway capacity.

Keywords

References

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History

  • Receive Date: 16 December 2014
  • Accept Date: 16 December 2014

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